This project has three primary aims: first, and orginally, to seek nucleases, which by virtue of their specificity, would be useful as tools in sequencing nucleic acids; second, to study the factors involved in regulation of nucleic acid metabolism; and third, to study alterations in nucleic acid metabolism in malignancy in order to determine whether any of these changes could serve as indicators for the presence or absence of disease. BIBLIOGRAPHIC REFERENCES: Pendergrast, W.J., Jr., Drake, W.P., Schmukler, M. and Mardiney, M.D. Jr. Correlation of Abnormal Profiles of Nucleolytic Activity to Cancer, In Control of Neoplasia by Modulation of the Immune Systems. Ed. Chirigos, M.A., New York, Raven Press, 1977. Neuwelt, E.A., Schmukler, M., Nizick, M.S., Jewett, P.B., and Levy, C.C. The Immunological Characterization of Several Human Ribonucleases Using Primary Binding Tests. Biochem. J., in press, 1977.